Question

a boy lifts a box of mass 5kg to a
height of 150 cm. What is the work done
by
the boy
?​

Answer 1

Given :-

Mass of the box = 5 kg

Height of the box lifted = 150 cm

To Find :-

The work done by the boy.

Analysis :-

Here we are given with the mass and the height.

In order to find the work done substitute the given values from the questions accordingly such that work done is equal to mass into gravity into height.

Solution :-

We know that,

• m = Mass
• w = Work done
• g = Gravity
• h = Height

Using the formula,

$\underline{\boxed{\sf Potential \ energy=Mass \times Gravity \times Height}}$

Given that,

Mass (m) = 5 kg

Gravity (g) = 10 m/s

Height (h) = 150 cm = 1.5 m

Substituting their values,

⇒ w = mgh

⇒ w = 5 × 10 × 1.5

⇒ w = 50 × 1.5

⇒ w = 75 J

Therefore, the work done by the boy is 75 J.

Answer 2

Answer:

Given :-

• A body lifts a box of mass of 5 kg to a height of 150 cm.

To Find :-

• What is the work done by the boy.

Formula Used :-

$\sf\boxed{\bold{\large{Work\: done\: =\: mgh}}}$

where,

• m = Mass
• g = Acceleration due to gravity
• h = Height

Solution :-

Given :

• Mass (m) = 5 kg
• Acceleration due to gravity (g) =10 m/s
• Height (h) = 150 cm = $\sf\dfrac{150}{100}$ = 1.5 m

According to the question by using the formula we get,

⇒ $\sf Work\: done\: =\: 5 \times 10 \times 1.5$

⇒ $\sf Work\: done\: =\: 5 \times 15$

➠ $\sf\bold{\red{Work\: done\: =\: 75\: J}}$

$\therefore$ The work done by the boy is 75 J .